In the production and shipping of articles, it is well known to have machinery commonly referred to as material handlers to ease the process of moving units or bulk material. Material handlers include a broad range of equipment including conveyors, feeders, cranes, hoppers and lifts. Lifts are designed to raise and lower objects or containers containing the bulk material. The lift is typically prove and with a material handling tool such as a pair of fork tines or a barrel gripper. In cases where the material handling tool is a barrel gripper, the lift can be designed to also invert the container, if desired.
The level of cleanliness of the material handler is typically dependent on the location in which the material handler is used. It would be expected that a material handler located in a food or pharmaceutical plant would be maintained at a higher level of cleanliness than a material handler located in a furniture warehouse, on a construction site, or in a conventional landfill. Lifts used in food or pharmaceutical plants to move bulk grains, chemicals or drugs must be cleaned regularly to avoid contamination of the end product. However, while the exterior of the lift must be cleaned, care must be taken not to foul the inner works of the lift.
It has been recognized that reducing to a minimum the size of any openings between the inner works and the exterior would reduce the likelihood of contamination, whether by cleaning solution or the material being handled, from entering the lift works. It therefore is known to create a longitudinal slot through which a member which supports the material handling tool projects, to have only the minimal size required for the longitudinal movement of the member. It has also been recognized that if the slot is lined with brushes that flex out of the way of the member as it moves longitudinally or has a pair of elastomeric sheets which substantially cover the slot, and a slit extending longitudinally between the sheets wherein the sheets deform out of the way of the member, these structures will prevent large objects from entering through the slot into the inner works. However, these structures have shortcomings with respect to limiting small objects or fluids from entering the interior, since these structures do not conform in tight sealing engagement with the movable member.
It is desired to have a lift that has a member that receives a material handling tool, an opening for allowing longitudinal movement of the member, and a seal for sealing the opening, thereby sealing the interior of the lift.